I was checking out youtube, and came across a guy who had a heat element coming up through the bottom of his igloo cooler. I'd like to add one to my sparge tank which is the same cooler. Anyone see any issues with this? Also, what do you use typically for sealing purposes? I assume some of it will touch the beer, so it has to be non-toxic. Is silicone the typical go to? Any particular type of silicon?

Try to use a weldless fitting with a lock nut, washer, high-temp silicone o-ring, etc. Silicone sealant CAN adhere to plastic (make sure it's 100% silicone so that it's food-safe), and I originally used sealant on my MLT. But it's less than ideal, and could potentially start leaking at any time - I'd be particularly worried about it so close to the heating element.